How does lightning form?
Lightning is the product of particles in a cumulo-nimbus or other large cloud formations rubbing together to form giant sparks that can form within these clouds or from the cloud to the ground or even from the ground to the cloud if conditions are right.
Lightning can form in almost any conductive environment from thunder clouds to volcanic eruptions clouds and pyro-cumulus clouds that form from large bushfires.
They are similar to static electricity charges you get when the air is dry and you rub two pieces of conductive material together and you get a zap, only much larger.
How does lightning help plants grow?
Lightning contains many nutrients that it absorbs from the surrounding elements. The heat produced from lightning interacts with the nitrogen and oxygen surrounding the lightning charge. The result is nitrates are formed.
When this nitrate is dissolved in the rain within the cloud, it becomes a natural fertiliser. This is why you see a greener and better grass a few days after a thunderstorm.
So basically, thunderstorms are giant fertilisers and in combination with high rainfall can turn once barren landscapes into flourishing landscapes especially if thunderstorms occur more than once over a period of time.
Lightning is also commonly associated with the beginning of life and how it may have formed on earth.